Tensioner fail

[gled49]

Here’s a drawing of the factory tool to set the height of the divider piston in the 930 tensioner.

[Dpmulvan]

Originally Posted by stownsen914

I recently disassembled some pressure fed tensioners to do the Woods mod. Getting those clips out wasn't a picnic. I plan to put them back in to reassemble. It appears that their purpose is to keep the piston from falling out when the tensioner is out of the engine. Perhaps it's just a convenience, as I suppose the piston is held captive once the tensioner is installed.

Is it possible to put the c clips back in?

[Jonny042]

Originally Posted by PeteKz

Another question about the tensioners:

As an experiment, I have been running the Quaker State 5W-30 full synthetic for the past 3000 miles. Why? because my main and rod bearing clearances are fairly tight, at .002"/.05mm, so a 5W-30 oil should be fine for the journals. It's an SP rated oil with a current additive package that has more moly to replace zinc and phosphorus. And 540 RAT rates it very highly in his wear tests.

See: https://540ratblog.wordpress.com/

I acknowledge that he recommends sticking with the manufacturer recommended viscosities in air cooled engines, typically 50 to 60 weight, because they typically do not control oil temperature as well as water-cooled engines do. Nevertheless, I'm trying it and monitoring the results. I will do an oil sample analysis soon, which will tell me whether there are higher wear metals or contaminants than normal. And I will share those.

But I bring this up here because I'm contemplating what effects, if any, thinner oil will have on the oil-fed tensioners which I have. It should allow the tensioners to move more easily against oil pressure and thinner oil in the tensioners. That may or may not be a good thing, but I haven't yet experienced strange noises at RPM up to 6500; although an engine at high RPM is making enough noise that I doubt I could hear any subtle changes in the noise level.

Any other thoughts or experience about viscosity and the tensioners?

Bravo!!! At the risk of turning this discussion into an oil thread, I'm interested in the results of this experiment. I have no problem believing a modern 5W30 synth can do everything better than 20W50 dino oil, even with the lower viscosity. IMO the pressure in the tensioner is controlled by the bleed valve and should not be viscosity dependent, the tensioning force will be the same.

[PeteKz]

I will post my oil sample test results in one of the oil threads, probably the "Ultimate Oil Science" one.